AC performance tune up times two systems. Mark changes his own filters. Inspect blowers, evaporators and ductwork. Downstairs is a 2021 model. I performed a leak search on both systems. Unfortunately both units are low on refrigerant. Downstairs is the newer r410a upstairs is r22 I am leaving a repair estimate in order to get the systems running at peak performance with refrigerant. Also leaving quotes for replacement for the upstairs since it is 14 years old.